Placer screen



' March 2,1943. A. v. HARRIS PLACER scum: Filed Dec.- 25, 1941 O n I on J p a. z fl :2

INVENTOR Tiflarralr I Alonzo- IIIIII'I'),

ATTOR N EYS Patented Mar. 2, 1943 UNITED STATES PATENT OFFICE PLACER SCREEN Alonzo V. Harris, Farmington, N. Mex.

Application December 23, 1941, Serial No. 424,167 6 Claims. (01. 209-506) My invention relates broadly to new and useful improvements in screens for use in placer mining.

An important object of my invention is the provision of a screen that is uniquely formed to eificaciously retain particles of gold washed thereacross by a stream of water in the manner conventional in placer mining operations.

Another object of my invention is the provision of a screen of the above-mentioned character that is uniquely constructed to cause the relatively fine gold particles suspended in the water to be deposited in one of a plurality of sockets provided in the upper surface of the screen, which sockets being uniquely formed to permit the sand particles and other debris to be washed across the screen and to permit the fine gold deposited in the sockets to be discharged through the openings that extend through the side walls of the sockets below the plane of the screen, the openings permitting the fine gold particles to egress from the sockets being unique in their formation to prevent clogging of the opening by the particles passing therethrough.

Other objects and advantages of my invention, will be apparent during the course of the following description.

In the drawing, forming a part of this specification, and wherein like numerals are employed to designate like parts throughout the same,

Figure 1 is a top plan view of a placer screen embodying my invention,

Figure 2 is an enlarged fragmentary vertical sectional view taken on the line 22 of Figure 1, and

Figure 3 is an enlarged fragmentary vertical sectional view taken on the line 3-3 of Figure 1.

In the accompanying drawing, wherein for the purpose of illustration, is shown a preferred embodiment of my invention, the numeral ID designates a screen for use in placer mining operations. The screen comprises a single length of sheet material, preferably metallic, and preferably of substantially greater length than width. Of course, the relative length and width of the sheet may be varied in accordance with the exigencies of any particular situation; however, the screen should be of slightly lesser width than the sluice in which it is mounted and it should be of a length sufficient to permit the solid particles suspended in the water flowing thereacross to settle onto the top surface thereof. Experience teaches that a length of approximately ten feet is suflicient for the conventional sized sluice, though obviously the length of the sheet must necessarily be determined by the size of the sluice in which it is received.

The opposite side marginal edges of the sheet are preferably reenforced by upstanding rails II and I2 and the end of the sheet adapted to face the current is provided with an upstanding end rail l3. The opposite end of the sheet is open to permit the water to flow from the sheet. The side rails II and I2 are of sufficient height to direct the stream of water across the sheet and to hold the same Within the compass thereof for its entire area. In operation, the sheet is inclined at a slight angle from the horizontal and with the open end thereof disposed below the closed end.

The upper surface of the sheet is provided with a plurality of sockets M, which sockets are arranged in spaced parallel rows and which rows extend diagonally of the sheet. Each of the rows of sockets are separated by a ridge I5, the acclivous surfaces l6 comprising its opposite sides, sloping downwardly and into the sockets, as best illustrated in Figure 3. The crest or crown of the ridges extends above the plane surface of the sheet and, by reason of their diagonal position relative thereto, they will deflect the water flowing over the sheet angularly toward the rail I l.

The sockets comprising each of the rows are of generally circular formation in plan and, as illustrated in Figures 1 and 2, each of the sockets is formed with a rectilinear elongated opening I'I, each of which openings extends normally to the ridges at either side thereof. The marginal edges I8 and I9 'of the openings are stretched whereby to extend in overlapping relation. The lower marginal edge l9 may be vertically spaced any selected distance from the upper marginal edge 3 and the portion thereof extending beyond the free edge of th upper marginal edge is bent abruptly angularly downwardly. The distance between the overlapping marginal edges of the openings may be adjusted or set so that only solid particles of a selected maximum size may pass therethrough. If the overlapping edges [8 and [9 were maintained in spaced parallel relation, it is obvious that the particles passing therethrough would become packed therein to clog the openings; however, by bending the lower edges l9 downwardly so that the spaced margins are outwardly divergent, any particles passing through the openings may pass freely between the margins.

In operation, the water and suspended solid particles traversing the screen will impinge against th confronting acclivity of each of the ridges I5. The fine gold, being heavy, will drag along on the top surface of the screen beneath the sand and gravel and settle in the sockets. The diagonal position of the ridges will cause the water and the particles suspended therein to swirl into the row of sockets in advance of the ridge. The water, therefore, does not flow directly against the openings I! but rather strikes the same angularly as it is deflected by the prejacent ridges I5. pended in the water will therefore be retained in the sockets and the lighter sand and gravelparticles will pass across the top surface of the screen. The unique positioning of the openings The heavy gold particles sus- 1 ll above the bottoms of the sockets will. permit the sockets to be efficacious in their action to retain the gold particles; however, the water pressure, and the slope of the socket walls will force the; gold, through openings and into the under current of the stream of water traversingjthe sluice. The larger debris, such asstones, leaves, bits of wood etc, will be swept over the ridges and through the open end of the screen bythe action of the water. Attention is again directed to the factthat the unique shape of the openings II will prevent thesmall particles from packing or clogging therein to render the screen inoperative or ineflicient in operation. The distance between the marginal edges l8 and I9 may be regulated by a suitabletool, whereby to limit the size of the particles which may pass through the opening and this operation may be readily accomplished in an efficient and expeditious manner.

It is to be understood that the form of; my invention, herewith shown and described, is to be taken asapreferred example of; the same, and that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of my. invention, or scope of the appended claims.

Having thus described my invention, I claim:

1 A placer screen, comprising a single length of sheet material the upper surface ofwhich is formed with a plurality of sockets, said; sockets being arranged in spaced parallel diagonally extending rows; and; said rows. being separated by ridges, the individual sockets comprising each of.

thesaid rows being spaced from each other and having an elongated opening extending normally tofthe said ridges, the marginal edges of the.

openings, extending in overlapping relation and the lower marginal edge. being bent downwardly in diverging relation with the said upper mar. ginal edge.

2. A' placer. screen. comprising a length of sheet material having a. plurality of diagonally extending rows of sockets in its upper surface, each of said rows being. separated by, ridges and each of said sockets being provided with an opening, which openings being located at one end below the crown of the ridges but above the bottom of the sockets.

3. A placer screen comprising a length of sheet material having a plurality of diagonally extending rows of sockets in its upper surface, each of said rows being separated by ridges and each of said sockets being provided with an opening, which openings being located at one end below the crown of the ridges but above the bottom of the sockets, the marginal edges of the openings being arranged in overlapping relation and spaced apart and the said lower marginal edge being bent abruptly to diverge from the upper marginal edge whereby to prevent clogging of the opening by sand particles passing therethrough.

4. A placer screen comprising a length of sheet material the upper surface of which is formed with. a, plurality of generally hemispherical sockets, each', of said sockets having an elongated opening and said sheet being formed with an acclivous surface beyond each of. the sockets whereby water. flowing over the sheet will strike against the said acclivous surface andv be deflected into thesaid sockets. t

5. A placer screen, comprising a length of sheet material the upper. surface of which is formed with a plurality of. sockets, each of said sockets being providedfwith an elongated opening. ex-

tending diagonally of the sheet, said sheet being formed with acclivities located rearwardly of the with a pluralityJof sockets, each of said sockets being provided. with an elongated opening ex;

tending diagonally of the sheet, said sheet being, formed with acclivities located rearwardly of-- the sockets and extending. normally to the said openings wherebywater flowing from the upper surface of the sheet will impinge against the said acclivities and be deflected in a swirling motion intothesaid sockets, the marginal edges of each of theopenings extending in vertically spaced overlapping relation and the said lower marginal edge being bent abruptly downwardly in a direction away. from the upper marginal edge whereby solid particles carried into the sockets with the water may have egress through the openings. the diverging relation of the upper and lower marginal edges permitting the solid particles of requisite size to pass through the opening to haveeasy. egress therethrough.

ALONZO V. HARRIS. 

